The utility model discloses an experiment system for tangentially filtering a high-pressure-resistant flat-plate RO membrane, which comprises a feeding tank, a pressure pump, a flat-plate RO membrane filtering device, a storage tank, a pressure gauge, a regulating valve and a safety valve, wherein a flat-plate RO membrane filtering device comprises a top board, a bottom board and a RO membrane; the top board is detachably connected with the bottom board; a rectangular groove is arranged on a position corresponding to a face where the bottom board is glued to the top board, therefore, a gallery is formed; and the RO membrane is arranged between the top board and the bottom board and is capable of separating the top board from the gallery on the bottom board. According to the utility model, the experiment system is feasible in a lab and can bear high pressure needed for tangentially filtering the RO flat-plate membrane; the experiment system comprises equipment needed for high-pressure filtering and can bear the high pressure so as to complete a reverse-osmosis filtering experiment; in addition, the experiment system also can conveniently observe pollution situations of a membrane on each filtering stage and is convenient to research pollution control technology.